Writing instrument



FIG. 1 is a top, front, side perspective view of a writing instrument according to the present design;

FIG. 2 is a rear view of the writing instrument of FIG. 1;

FIG. 3 is a front view of the writing instrument of FIG. 1;

FIG. 4 is a left side view of the writing instrument of FIG. 1;

FIG. 5 is a right side view of the writing instrument of FIG. 1;

FIG. 6 is a bottom view of the writing instrument of FIG. 1; and,

FIG. 7 is a top view of the writing instrument of FIG. 1. 

CLAIM The ornamental design for a writing instrument, as shown and described. 